In a manufacturing method of semiconductor devices, a plasma process as a dry process for processing a substrate by using plasma of a processing gas is performed to carry out a film forming process or an etching process on the substrate. In the plasma process, the plasma of the processing gas is attracted onto the substrate so that high anisotropy can be obtained and the process can be performed even inside a pattern with a narrow opening width. However, since it takes a long time to complete the process due to a low processing speed, the processing speed needs to be improved. Furthermore, damage to a device due to an abnormal discharge or a charging damage in the substrate charged by the plasma has been a serious problem yet to be solved.
Further, since such plasma process is performed in a high-vacuum processing vessel, expensive peripheral equipment such as a dry pump, a turbo molecular pump or the like needs to be installed therewith. Moreover, since the processing vessel needs to have a pressure-resistant structure and the size of the processing vessel keeps increasing due to the enlargement of a substrate size, apparatus manufacturing cost is expected to keep further rising.
In addition, the increase in the substrate size makes it difficult to maintain in-plane process uniformity of the substrate. Thus, there has been an increasing demand for an alternative process to the conventional dry process such as the plasma process.
Meanwhile, for instance, in a wet process for processing a substrate by immersing the substrate in a processing solution, high in-plane process uniformity of the substrate can be achieved without any risk such as a charging damage in a device or the like. Further, since such wet process is performed under an atmospheric pressure, equipment can be manufactured at a low cost. However, a reaction by the processing liquid progresses isotropically, and thus, it is difficult to form a pattern with a high aspect ratio through an anisotropic process, e.g., etching. Moreover, since it is difficult to flow the processing liquid into a narrow opening portion, there has been difficulty in applying the wet process to a film forming process for burying a material in such pattern.
Meanwhile, disclosed in Japanese Patent Laid-open Application No. 2004-121962 (paragraphs [0031]˜[0037]) is a technology for cleaning industrial equipment or the like by using bubbles of a micrometer (nanometer) scale, so-called micro-bubbles (nano-bubbles), and also disclosed in Japanese Patent Laid-open Application No. 2005-245817 (paragraphs [0012]˜[0013]) is a technology for forming the nano-bubbles stably. However, neither of these documents mentions anything about the means for solving the above-stated problems.